Tier 1 · Strong research evidence
Why this tier: Systematic Review / Meta-Analysis
Augmentative and Alternative Communication (AAC) in Autism
Published 29 June 2026 · 4 min read
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AAC means ways to communicate that add to speech or stand in for it, such as signs, picture boards and devices that speak. A review that brought together 17 earlier research reviews found it helps autistic children communicate. It does not stop them learning to talk. There is no single best system: the right one depends on the child.
What this research found
- AAC works for autistic children. AAC stands for augmentative and alternative communication: ways to communicate that add to speech or stand in for it, such as signs, picture boards and devices that speak. One study brought together 17 separate reviews of the research. It found AAC ranged from effective to highly effective at helping autistic children communicate. It helped most with learning to ask for things, which is often the first step in building communication.
- Using AAC does not hold back speech. Research consistently shows that starting AAC does not slow down or stop a child from learning to talk. In fact, growing evidence suggests it can support speech, along with other communication skills.
- Around 25–50% of autistic children do not develop spoken language they can use day to day. So many children stand to gain a great deal from AAC, and the earlier it starts, the better. Specialists in this field see waiting to find out whether speech comes on its own as unnecessary, and as ethically troubling.
- AAC can reduce frustration and challenging behavior. When a child gains a reliable way to say what they want and need, research shows a real drop in distress. It also shows a drop in the difficult behaviors that can come from struggling to communicate.
- There is no single "best" AAC system. Options range from no-tech (gestures and signs) to low-tech (picture boards) to high-tech (devices and apps that speak aloud). The right choice depends on the child's strengths, their motor skills (how well they control their hands and body), where they spend their day, and the people around them. Of the specific AAC methods, the Picture Exchange Communication System (PECS) currently has the strongest research behind it. In PECS, a child learns to hand over a picture to ask for something.
What this means for caregivers of autistic children
- You don't have to wait. If spoken communication is hard for your child, you can look into AAC now. Research supports offering communication tools early rather than holding off to see if speech develops. Both can happen at the same time.
- Everyone around your child has a part to play. AAC works best when the people in a child's life all use it, and show how it is used, throughout the day. That means parents, brothers and sisters, teachers and support workers, and not only during therapy sessions. This is sometimes called "aided language stimulation": you point to the pictures or symbols on your child's system as you talk. Even small moments of showing make a real difference.
- Think beyond the device. Even if a high-tech device is your child's main way to communicate, it helps to also build some low-tech or no-tech skills, like gestures or a simple picture board. These help when the device isn't practical, such as at the swimming pool or on a busy playground.
- Ask about a proper assessment. A speech-language pathologist (SLP), also called a speech therapist, or an AAC specialist can help match your child to the system that fits them best. They take into account your child's motor skills, how they learn and their daily surroundings. Insurance or funding support may also be available for devices.
Important caveats
- The quality of the research varies. The overall direction of the evidence is positive. But the review found that many individual studies had weaknesses in how they were designed. That makes it hard to draw firm conclusions for every child or every AAC system. Results for high-tech devices that speak depend heavily on how much training and ongoing coaching comes with them.
- Up to 60% of AAC systems are abandoned. Research from Autism Ontario points out that a device or system on its own is not enough. Without steady training, support and follow-up from a qualified team, many AAC tools end up set aside. Families and professionals both need to keep at it.
- Some promoted "communication" methods are not safe. These are Facilitated Communication, Rapid Prompting Method and Spelling to Communicate. They are not evidence-based, meaning research has not shown they work, and they have been linked to serious harms. Professional bodies, including the American Speech-Language-Hearing Association, have issued formal warnings against them. Always talk to a qualified clinician before starting any communication program.
The science behind it
This part is written for researchers, so it gets technical. Reading it anyway is what researchers do: checking how a finding was reached, not just what it says. It’s slow going at first and gets easier after your first few articles. Skipping it is fine too.
A 2016 systematic review of 17 systematic reviews of AAC intervention research for autistic children up to age 21 rated AAC interventions effective to highly effective, particularly for teaching requesting. AAC does not hinder spoken language development, and growing evidence suggests it may support it; PECS has the strongest research base among specific methods.
Source: Iacono, T., Trembath, D., & Erickson, S. (2016). The role of augmentative and alternative communication for children with autism: current status and future trends. Neuropsychiatric Disease and Treatment, 12, 2349. Supplemented by Autism Ontario, Autism Society of NC, Vanderbilt TRIAD, and the National Autistic Society. Evidence level: Tier 1 — Systematic Review / Meta-Analysis Domain: Communication
About this research
The primary source is a peer-reviewed systematic review published in Neuropsychiatric Disease and Treatment (2016) by researchers at La Trobe University and Griffith University in Australia. The authors searched three major academic databases and identified 17 systematic reviews of AAC intervention research for children with autism (up to age 21), published between 2000 and 2016. They extracted data on study quality, effect sizes, and evidence for effectiveness across different AAC types and outcomes. This summary also draws on complementary expert guidance from Autism Ontario, the Autism Society of North Carolina, Vanderbilt TRIAD, and the National Autistic Society, all of which align with the peer-reviewed evidence.
The research in its own terms. The findings above are written in everyday words. Here are the technical terms, so you can match them to the papers:
- Effectiveness: across the 17 systematic reviews, AAC interventions were rated effective to highly effective, particularly for teaching requesting.
- Speech: AAC does not hinder spoken language development, and growing evidence suggests it may support it.
- Need: around 25–50% of autistic children do not develop functional spoken communication.
- System types: no-tech (gestures, signs), low-tech (picture boards) and high-tech (speech-generating devices and apps); outcomes with speech-generating devices depend heavily on training and ongoing coaching. PECS has the strongest research base among specific methods.
- Implementation: communication partners modeling AAC throughout the day (aided language stimulation); up to 60% of AAC systems are abandoned (Autism Ontario).
Read the original
Source: Iacono, T., Trembath, D., & Erickson, S. (2016). The role of augmentative and alternative communication for children with autism: current status and future trends. Neuropsychiatric Disease and Treatment, 12, 2349. https://doi.org/10.2147/NDT.S95967. Supplemented by: Autism Ontario AAC Fact Sheet (2026); Autism Society of NC AAC Guide (2023); Vanderbilt TRIAD AAC and Autism Educator Guide (2023); National Autistic Society / Higgins-Walsh, E. (2023).
Reviewed by Bhavin Solanki, caregiver parent. This is informational content, not medical advice — see our disclaimer.